SG1825

LIN D O C #: 1825 SG1825C/SG2825C/SG3825C HIGH-SPEED CURRENT-MODE PWM T H E I N F I N I T E P O W E R O F I N N O V A T I O N NOT RECOMMENDED FOR NEW DESIGNS DESCRIPTION The SG1825C is a high-performance pulse width modulator optimized for high frequency current-mode power supplies. Included in the controller are a precision voltage reference, micropower start-up circuitry, softstart, high-frequency oscillator, wideband error amplifier, fast currentlimit comparator, full double-pulse suppression logic, and dual totempole output drivers. Innovative circuit design and an advanced linear Schottky process result in very short propagation delays through the current limit comparator, logic, and output drivers. This device can be used to implement either currentmode or voltage-mode switching power supplies. It also is useful as a series-resonant controller to frequencies beyond 1MHz. The SG1825C is specified for operation over the full military ambient temperature range of -55°C to 125°C. The SG2825C is characterized for the industrial range of -25°C to 85°C, and the SG3825C is selected for the commercial range of 0°C to 70°C. K E Y F E AT U R E S s IMPROVED REFERENCE INITIAL TOLERANCE (±1% max.) s IMPROVED OSCILLATOR INITIAL ACCURACY (±3% typ.) s IMPROVED STARTUP CURRENT (500µA typ.) s PROP DELAY TO OUTPUTS (50ns typ.) p 10V TO 30V OPERATION p 5.1V REFERENCE TRIMMED TO ±1% p 2MHZ OSCILLATOR CAPABILITY p 1.5A PEAK TOTEM-POLE DRIVERS p U.V. LOCKOUT WITH HYSTERESIS p NO O...